Walk-in type coolers, such as those commonly found in convenience stores today, are typically constructed of insulated wall, ceiling and floor panels that are fastened snugly together. The panels are usually comprised of foam insulation, such as expanded polystyrene and polyurethane encased within thin metallic sheets. The panel ends are shaped to fit together in tongue-and-groove fashion. They are provided with latch means for drawing and holding them snugly together. The latches themselves are commonly comprised of a hook assembly mounted to one panel for latching engagement with a pin assembly mounted to an adjacent panel. Kason Industries, Inc. of Shenandoah, Ga. manufactures and sells one line of such hook and pin type panel fasteners. Similar latches are shown in U.S. Pat. Nos. 3,565,469, 4,223,500, and 4,417,430. Some of these are formed in situ during formation of the insulation into the shape of blocks while others are designed to be mounted to the panels after they have been formed.
The latches used in interlocking adjacent panels together have had problems associated with their incorporation and use. For example, where the latch members have not been formed in-situ as the insulation is formed into blocks, a cavity has had to be cut into the insulation to receive the hook and pin assemblies. This has been tedious and inefficient and has often resulted in an unsightly product. Also, regardless of the method of incorporation, when the latch hook has been rotated into gripping engagement with the pin, only the local area of the panel about the bar assembly has been drawn snugly against the other panel.
Accordingly, it is a general object of the present invention to provide an insulated panel with an improved interlock mechanism which overcomes the just described problems associated with those of the prior art latches, and to provide an improved method of constructing such insulated panels.